Motorcycle skidplate

ABSTRACT

A motorcycle skidplate is disclosed to protect motorcycle oil vessels and lines from rupture by foreign objects, resulting in oil being interposed between a motorcycle wheel and the surface being traversed, causing a loss of control of the motorcycle. In particular, oil pans exposed below the motorcycle frame are susceptible to rupture by foreign objects during use.

This invention relates to an after-market safety feature for motorcycles to prevent rupture of the oil pan on certain models of motorcycle. A motorcycle typically comprises a frame, a front wheel, a rear wheel, an engine and a drive train. On some models of motorcycle, the oil pan for the engine is protected by the frame from any damage from rocks, curbs or abrupt grade changes. In other models, the oil pan extends below the frame and is susceptible to damage from objects that rupture the oil pan and release oil beneath the rear wheel. Such ruptures can have catastrophic, even fatal, consequences for the rider because oil on tires causes a loss of control of the motorcycle, with a risk of collision with vehicles, trees, poles and other objects.

SUMMARY OF THE INVENTION

This invention is a plate secured to a motorcycle frame that extends below the oil pan and is spaced sufficiently from the oil pan to allow the plate to flex and absorb impact energy without breaking the pan itself. The plate must cover the pan to protect it from impact from road objects while at the same time not interfering with the operation of other features of the motorcycle, such as the kickstand and the passenger foot peg. Preferably, the plate is secured fore and aft and has a curvature that enables the plate to flex upon impact with an object to absorb energy without touching the oil pan.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a conventional motorcycle with the skidplate of this invention below the oil pan.

FIG. 2 is a left side view of the plate of this invention.

FIG. 3 is an isometric view of the plate before installation.

FIG. 4 is a bottom view of the oil pan to be protected by the invention.

FIG. 5 is a left side view of a motorcycle upside down, showing the exposure of the oil pan protruding beyond the frame.

FIG. 6 is an isometric view of the underside of the motorcycle with the protective plate installed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An example of the type of motorcycle that has the oil pan exposed beneath the frame is the FXD series of Harley-Davidson motorcycles sold under the “DYNA” trademark. This is one type of motorcycle that has an exposed oil pan below the frame. With modifications apparent to one skilled in the art, the plate can be adapted to any other model of motorcycle having an exposed oil pan.

FIG. 1 is a side view of a conventional motorcycle having the usual prior art parts of a front wheel A, and a rear wheel B for traversing a road surface C. The driver sits on seat D, and the passenger has a back rest E. An optional part for motorcycles is a passenger foot peg 41 secured to frame 38 to allow the passenger to rest a foot on foot rest 45 attached to peg 41. The motorcycle at rest is held upright by kickstand 29, also prior art. The invention is described with respect to the following Figures.

FIG. 2 is a view of the left side of a plate according to the invention with a forward lip 12 adapted to engage the frame of the motorcycle and an aft tube 13 welded to plate 14. Tube 13 is designed to encircle the passenger foot peg mounting bracket to be described presently. Plate 14 is conveniently made of 10 gage steel to be able to absorb the shock of impact between a motorcycle with a rider and perhaps a passenger striking a hard object on the surface C being traversed (FIG. 1). Plate 14 is bent at suitable locations to provide flexure as well as accommodate the bottom carriage of the particular model of motorcycle. In the embodiment shown, lip 12 is approximately a 90 degree bend about one half inch from the forward end of the plate 14. A second bend 16 of approximately 30 degrees about five inches from the lip allows the plate 14 to clear the protruding oil pan (not shown in FIG. 1). Span 17 from lip 12 to bend 16 provides curvature desired for allowing plate 14 to flex. The longest span 18 between bend 16 and bend 19 (approximately eight inches in this embodiment) extends beneath the oil pan to protect against rupture. Bend 19 is about 20 degrees upward to extend to bend 21, which is about 10 degrees downward to make the shortest span (less than 2 inches). The last span 23 extends from bend 21 to tube 13, the aft terminus of plate 14. In all, plate 14 is generally curved to allow flexing, yet rigid enough to repel impact from hard objects.

Of course, the bends and distances are intended to accommodate the “DYNA” motorcycles having specific configuration. Other models will have other configurations, but all meet the requirement for rigidity to protect the relatively fragile oil pan (typically of cast aluminum) while flexing sufficiently to absorb impact energy.

FIG. 3 is a generally top view of the plate of FIG. 1. The right side (top) covers the oil pan (not shown). The left side (bottom) is notched to accommodate the movement of the kickstand and spring on the left side of the motorcycle. Lip 12 secures plate 14 to the frame and welded tube 13 encircles the mount for the passenger foot peg 41. The bends 16, 19 and 21, separating segments 17, 18, 22 and 23 are barely visible in FIG. 3.

FIG. 4 is a bottom view of an oil pan cover 26 for a DYNA motorcycle. When a motorcycle strikes a rock, curb or other obstacle without the plate of the present invention installed, the usual rupture at the lower left corner 27, releasing oil directly in front of the rear tire, causing the loss of control by the cyclist. By protecting the cover 26 from damage, such accidents can be avoided.

FIG. 5 is a left side view of an upended DYNA motorcycle showing the extent that oil pan cover 26 protrudes beyond (below) the left frame 28 of the motorcycle. Kickstand 29 is retracted by spring 31 which is secured at point 32 on the leg of kickstand. The other end of the spring 31 is secured to a plate 33 joining forward frame cross member 34 and cross member 36 by bolt 37.

Left frame 28 and right frame 38 converge aft of the cover 26 and are connected at tube 39 that rotatably holds passenger foot peg 41. Arm 42 attached to right frame 38 and arm 43 attached to left frame 28 secure peg bracket 44 about which peg 41 rotates. Peg 41 is held in place for passenger use by bolt 46. All of the aspects of FIG. 5 are standard equipment on the DYNA motorcycle.

FIG. 6 illustrates how the plate 14 covers the oil pan cover 26 when installed. The forward lip 12 fits under the forward cross member 24 (when upright above the member 24 to allow flexing inwardly). Plate 14 passes over the cover 26 in FIG. 6. The aft end of plate 14 has tube 13 grasping bracket 44 of the peg 41 between frame arms 42 and 43. Kickstand 29 is extended in FIG. 6. When stowed, kickstand 29 fits next to plate 14. Notch 51 in plate 14 accommodates spring 31 in the stowed position and notch 52 permits the kickstand 29 to rest without contacting the plate 14. Of course, different configurations can be made for plate 14 for different features of a motorcycle, as will be appreciated by one skilled in the art. The dimensions and shape are merely illustrative and are not intended to limit the invention.

The invention is used on all motorcycles that need protection from rupture of the oil pan or other susceptible parts of the motorcycle, such as oil lines and vessels, that can be struck by rocks, curbs, or other hard objects. While the Harley-Davidson model here described was the initial motorcycle for which a skidplate was constructed, one skilled in the art will be able to adapt the dimensions, angles and configuration for motorcycles of different design. The rider of the model in question suffered a fatal accident in 1999 when the impact of an obstacle on the oil pan ruptured it and caused oil to spread below the rear wheel causing loss of control. My acquaintance with the rider provided the motivation for the present invention. However, it is contemplated that the invention is used with other models of motorcycles that need impact resistance at critical locations like oil pans. In short, the invention encompasses motorcycle skidplates of all configurations within the skill of the art, and not just the “DYNA” model. 

1. (canceled)
 2. A skidplate as in claim 8 comprising a body of steel plate shaped to be secured to the motorcycle frame in at least two mounting points fore and aft of the oil pan of the motorcycle to shield the oil pan form foreign objects below the oil pan.
 3. A skidplate as in claim 2 wherein the steel plate is composed of at least ten gage steel.
 4. A skidplate as in claim 2 wherein the oil pan is exposed below the motorcycle frame and the body is bent to be secured to ,the frame fore and aft of the oil pan and to generally curve below the oil pan to shield it from foreign objects.
 5. A skidplate as in claim 4 wherein the body is spaced sufficiently from the oil pan to allow the body to flex upon impact with a foreign object to absorb the energy of impact without contacting the oil pan.
 6. A skidplate as in claim 4 wherein the body has a forward lip to engage the motorcycle frame and allow the skidplate to flex inwardly towards, but not contacting, the oil pan, and has an aft appendage to engage a mounting bracket affixed to the frame.
 7. A method of protecting a motorcycle oil pan that extends below the frame of a motorcycle by securing a skidplate that extends below the oil pan to the frame in order to absorb the impact of foreign objects without rupturing the oil pan.
 8. In a motorcycle comprising a frame, a front wheel, a rear derive wheel, an engine disposed between the front wheel and the rear drive wheel including a lubricating system and an oil pan beneath the engine, a drive train providing the engine output to the rear drive wheel said drive train having no cooperation with the lubricating system of the engine, the improvement comprising a skidplate secured fore and aft to the frame by nonpivotal fasteners and located below the oil pan and forward of the rear drive wheel and capable of flexing inwardly but not twistably in relation to the fame to prevent rupture of the oil pan by objects such as rocks, curbs or abrupt grade changes on the surface being traversed by the motorcycle. 